Today Microsoft announced that they’ve acquired AdECN, described as an online “stock exchange” for advertisers and those seeking to advertise online.

The company is privately held and terms of the sale weren’t disclosed.

Unlike Google’s Adwords program, participants in AdECN’s program “bid” for a spot on their exchange, costs for these seats vary according to the members volume and quality of traffic.

It’ll be interesting to see if Microsoft will be able to put a dent in the online advertising arena, what are your thoughts?